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June 25-26, 2016

Logical and semantic frameworks are formal languages used to represent
logics, languages and systems. These frameworks provide
foundations for formal specification of systems and programming languages,
supporting tool development and reasoning.

The objective of this workshop is to bring together theoreticians and
practitioners to promote new techniques and results, and to
facilitate feedback on the implementation and application of such techniques and
results in practice.

Topics of interest to this forum include, but are not limited to:

Automated deduction

Applications of logical and/or semantic frameworks

Computational and logical properties of semantic frameworks

Formal semantics of languages and systems

Implementation of logical and/or semantic frameworks

Lambda and combinatory calculi

Logical aspects of computational complexity

Logical frameworks

Process calculi

Proof theory

Semantic frameworks

Specification languages and meta-languages

Type theory

LSFA 2016 also aims to be a forum for presenting and discussing work
in progress, and therefore to provide feedback to authors on their
preliminary research.
The proceedings are produced after the meeting,
so that authors can incorporate this feedback in the published
papers.

Call for Papers

Contributions should be written in English and submitted in the form of full
papers with a maximum of 16 pages including references or short papers
with a maximum of 6 pages including references. Additional technical material
can be provided in a clearly marked appendix which will be read by reviewers at
their discretion. Contributions must also be unpublished and not submitted
simultaneously for publication elsewhere.

The papers should be prepared in LaTeX
using ENTCS style. The submission should be in the form of a PDF file uploaded
to Easychair:

The workshop pre-proceedings, containing the reviewed extended abstracts, will
be handed-out at workshop registration. After the workshop the authors of both
full and short papers will be invited to submit full versions of their works for
the post-proceedings to be published in ENTCS.
At least one of the authors should
register for the conference. Presentations should be in English.
Important Dates

Submission: April, 15th 2016 April, 22th (extended deadline)

Notification: May, 14th 2016

Final pre-proceedings version due: May, 24th 2016

According to the quality of proceedings, authors will/would/might be invited to
submit an improved version of their paper for a special issue.
Previous LSFA special issues
have been published in journals such as J. IGPL and TCS (see http://lsfa.cic.unb.br).

Invited Speakers

Abstract. A common theme in program verification is to relate two programs, for instance
to show that they are equivalent, or that one refines the other. Such relationships
can be formally established using relational program logics, which are tailored to
reason about relations between two programs, or product constructions which allow
to build from two programs a product program that emulates the behavior of both
input programs. Similarly, product programs and relational program logics can
be used to reason about 2-safety properties, an important class of properties that
reason about two executions of the same program, and includes non-interference and
continuity, and other notions such as truthfulness (a concept from game theory) and
differential privacy.

In this talk, I shall present an overview of relational program logics and product
programs and explore their relationship, both in the context of imperative and
higher-order languages.

Abstract.
Logics and type systems are closely related: given a sufficiently general type system,
many logics can be defined in terms of typed signatures. This is the design of the
Edinburgh Logical Framework (LF) [4], to take a prototypical example, where the
dependently typed λ-calculus is taken as a uniform representation of the syntax, rules,
and proofs of candidate object logics. The opposite perspective is comparatively less
common: in a suitably general logic, a wide variety of type systems can be defined
in terms of adequate relational encodings [2].

This talk demonstrates this latter perspective by showing how to capture:

dependently typed λ-terms (LF);

refinement and intersection types;

any functional pure type system; and

modal and substructural type systems

in an extension of the two-level logic approach [5,3] to specification and reasoning,
implemented as a fork of the Abella theorem prover [1]. Each type system is
represented by:

a simply typed specification in a fragment of λ-Prolog that encodes a relational
interpretation of types as logic programs;

an intuitionistic reasoning logic to reason inductively about derivations in the
specification logic; and

a flexible family of translation layers designed to dynamically mediate between
typing judgements and their relational interpretations.

One benefit of this perspective is that extra-logical aspects of type signatures, such as
subordination, that are often seen as primitives of type systems can be given a logical
treatment, which can transform trusted procedures into certifying procedures [6].

Abstract While type systems for more traditional programming abstractions have been
rooted on pure logical principles, im the sense of Curry-Howard correspondences,
the connections between session-based concurrent programming languages and their
logically motivated type disciplines only started to be better understood recently.
In this talk, we review some of our recent work on the theme, and discuss extensions
to non-deterministic interaction.

Abstract.The success of propositional satisfiability (SAT) solvers is underscored by their
ubiquitous use in practical applications. Whereas many practical applications can
be cast as decision problems, for which a single query to a SAT oracle suffices,
for many other applications, SAT oracles are called multiple times. For example,
this is the case when solving decision problems with abstraction refinement, e.g.
bit-vector formulas in SMT. This is also the case when solving decision problems in
higher levels of the polynomial hierarchy, e.g. QBF. Moreover, many computational
problems are naturally formulated as function (or search) problems, and can be
solved with a number of queries to a SAT oracle. This talk overviews problem-
solving based on multiple queries to a SAT oracle, focusing on approaches for solving
function problems.

The talk presents a number of function problems defined on
Boolean formulas and shows how most of these problems can be reduced to the
problem of computing a minimal set subject to a monotone predicate. The talk also
surveys a number of algorithms for the MSMP problem, highlighting the worst-case
number of SAT oracle queries. Finally, the talk overviews ongoing research in the
area of problem solving with SAT oracles.